PVC/纳米CaCO_3复合材料的制备及其性能研究

采用硅烷偶联剂KH-570对纳米碳酸钙进行表面处理,然后通过熔融共混法制备聚氯乙烯/纳米碳酸钙(PVC/nano-CaCO3)复合材料,用透射电镜观察了nano-CaCO3粒子在PVC基体中的分散状况。随着nano-CaCO3用量的加大,复合材料的冲击强度和失重残余量都有所提高,热分解温度变化不大,玻璃化转变温度先下降然后又有所增加。     

表面改性纳米碳酸钙原位悬浮聚合PVC的制备与性能研究

采用湿法表面改性的纳米碳酸钙(nano-CaCO3)与VCM原位聚合,制备了nano-CaCO3原位聚合PVC树脂(简称原位PVC树脂),研究了其力学性能、加工性能、微观形貌和热稳定性等。结果表明:①nano-CaCO3能够很好地分散在PVC树脂中,对PVC基体产生很好的补强作用;与普通PVC试样相比,原位PVC试样缺口冲击强度提高到13.3 kJ/m2,效果显著;其加工性能也得到了提高。②试样冲击断面的扫描电子显微镜照片表明原位PVC试样为韧性断裂,普通PVC试样为脆性断裂。③DSC试验表明,原位PVC树脂的热稳定性优于纯PVC树脂。     

PVC/(VC/BA)/纳米CaCO3复合材料的研制及其力学性能研究

通过对纳米碳酸钙(nano-CaCO3)表面处理及其对聚氯乙烯(PVC)、氯乙烯-丙烯酸丁酯共聚物(VC/BA)、nano-CaCO3三元复合体系加工工艺的考察,研制了PVC/(VC/BA)/nano-CaCO3复合材料,并对其力学性能进行了研究.结果表明以nano-CaCO3与VC/BA共聚物先制成复合母粒,再与PVC进行共混的二次分散成型工艺,比传统的将三者直接进行共混的一次分散成型工艺更有利于纳米粒子在基体中的分散,所制材料的力学性能更优.当复合母粒中VC/BA与nano-CaCO3的比例为2∶3时,材料的力学性能最佳,nano-CaCO3和VC/BA能协同增韧PVC,并且nano-CaCO3对材料具有补强作用,使材料在强度保持基本不变的情况下冲击性能得到大幅度提高,当PVC和复合母粒质量比为100∶20时,材料的冲击强度达到49.5kJ/m,是纯PVC(PVC的冲击强度为4.9kJ/m)的10倍,拉伸强度仍高达51.0MPa.     

反应挤出PU/纳米CaCO3增强增韧PVC

在考察聚氯乙烯/聚氨酯/纳米碳酸钙(PVC/PU/nano-CaCO3)反应挤出工艺的基础上,结合PU的反应特点,将表面处理的nano-CaCO3利用超声辐照技术并经搅拌分散于L-MDI中,采用反应挤出一步法制备了PU/nano-CaCO3共同增强增韧的PVC复合材料,并时其力学性能进行了研究.结果表明:PU/nano-CaCO3的质量配比为4:1时,增韧效果最佳,PU和nano-CaCO3能协同增韧PVC,且nano-CaCO3具有增强作用,当PVC/PU/nano-CaCO3质量比为100:20:5时,材料的综合性能最优.冲击强度达到58.3 kJ/m3,拉伸强度为51.5 MPa,增强增韧PVC效果显著.     

改性纳米CaCO_3填充PVC复合材料力学性能和转矩流变性能研究

通过熔融共混法制备了PVC/改性nano-CaCO3复合材料,并测试了复合材料的力学性能和转矩流变性能。结果表明:PVC/改性nano-CaCO3复合材料的力学性能比PVC/未改性nano-CaCO3均有所提高;PVC/改性nano-CaCO3复合材料在塑化过程中各阶段的扭矩及塑化时间比PVC/未改性nano-CaCO3均有所下降,其中超分散剂的改性效果最好。     

表面处理对原位悬浮聚合制备PVC／纳米碳酸钙复合材料的影响

对纳米碳酸钙进行表面预处理，在纳米碳酸钙粒子表面包覆上一薄层有机高分子，降低纳米粒子的高表面能，调节疏水性，改善其与有机基料之间的润湿性和结合性，从而达到与氯乙烯等有机物亲和良好的状态，防止纳米碳酸钙粒子自身的团聚，将经过表面处理和未处理的纳米碳酸钙粒子分别在5L和50L反应釜中与氯乙烯单体进行悬浮聚合，使纳米碳酸钙粒子原位复合到PVC中，将聚合完毕的PVC粒料浆液进行透射电镜，扫描电镜观察，比较纳米碳酸钙的表面处理对于原位悬浮聚合法制备PVC／纳米碳酸钙复合材料的影响。     

PVC/HfA/MMA/nano-Al(OH)_3复合材料性能的研究

采用丙烯酸六氟丁酯(HfA)和甲基丙烯酸甲酯(MMA)在纳米Al(OH)3(nano-Al(OH)3)颗粒进行表面聚合,使nano-Al(OH)3表面成亲油性,从而与聚氯乙烯(PVC)颗粒的相容性得到提高。在PVC聚合后期加入这种改性剂,纳米粒子包覆在PVC颗粒表面,改性PVC的综合性能得到改善。最佳试验反应条件为:HfA/MMA/nano-Al(OH)3的配比为3∶5∶92,PVC聚合后期加入占改性PVC树脂含量8%的HfA/MMA/nano-Al(OH)3复合材料,制备出的改性PVC树脂混合料的力学性能和耐热抑烟性能均比空白样品大幅提高。     

纳米CaCO_3的接枝改性及其填充PVC复合材料的性能

采用表面原位接枝聚合在纳米CaCO3颗粒表面引入聚甲基丙烯酸甲酯(PMMA)或聚丙烯酸丁酯(PBA),用共混法制备了纳米CaC03/PVC复合材料,研究了不同界面特性时纳米CaCO,/PVC复合材料的力学性能.研究结果表明:通过表面原位接枝聚合反应可以在纳米CaCO3颗粒表面接枝PMMA和PBA;表面接枝聚合改性大大促进了纳米CaCO3粒子在PVC基体中的分散行为,增加了复合材料的拉伸强度以及与聚合物的界面粘接强度,但复合材料的冲击强度有所下降.     

强界面PVC-U/nano-CaCO3的制备与力学性能研究

使用自主合成的端羧基聚酯和端叔胺基羧酸分别对水乳液中的nano-CaCO3进行表面处理,制备了可与PVC形成界面分子物理纠缠或热可逆交联的强界面结合能力的nano-CaCO3.研究了PVC-U/nano-CaCO3的力学性能与CaCO3的表面性质、填充量及表面处理剂分子量等因素的关系.研究结果表明,提高界面结合强度可改善CaCO3在基材中的分散状况并提高PVC-U/nano-CaCO3的屈服强度,却对于提高PVC的冲击能力无明显效果.     

改性剂对PVC/稻壳粉木塑复合材料性能的影响

采用改性nano-CaCO3、POE-g-MAH和EVA-g-MAH改善PVC/稻壳粉木塑复合材料性能。研究了改性剂的用量和种类对木塑复合材料力学性能、维卡软化点和流变性能的影响;用SEM观察复合材料冲击断面。结果表明:改性nano-CaCO3可显著提高木塑复合材料的冲击强度、弯曲强度和维卡软化点,复合材料的综合性能最好。当加入7.5份nano-CaCO3时,复合材料的冲击强度、弯曲强度和维卡软化点分别提高了92.16%、24.89%和13.77%;随着nano-CaCO3含量的增加复合材料的表观黏度逐渐升高,表面光滑度得到改善。     

Miscibility of PVC with chlorinated PE and chlorinated PVC

Miscibility of PVC with chlorinated PE and chlorinated PVC was reviewed. The miscible region of chlorine content ranged from 44 wt% to 65 wt%, which was not symmetric to the chlorine content of PVC, 56.7 wt%. Two group contribution methods were used to calculate solubility parameters of polymers. The results of solubility parameters showed a more symmetric miscible region with respect to the value of PVC. However, the ranges of miscibility were different. It was 2.3 (J/cm 3 ) 0.5 in a three-dimensional method and was 1.5 (J/cm 3 ) 0.5 in the Fedors method.     

PVC/高分子表面修饰CaCO3复合材料的加工性能研究

采用液态高分子改性剂对CaCO3进行包覆改性,得到高分子表面修饰CaCO3(CLCC)。使用转矩流变仪、紫外可见分光光度计及白度测定仪对聚氯乙烯(PVC)/CaCO3复合材料和PVC/CLCC复合材料的加工性能进行了研究。结果表明,CLCC颗粒的加入可以缩短PVC的塑化时间,改善其加工性能,提高PVC生产效率;而抑制了PVC在熔融加工过程中的降解;PVC/CLCC复合材料的白度保持率高于PVC/CaCO3复合材料。     

Small-angle scattering studies of PVC and PVC blends

Small-angle X-ray and small-angle neutron scattering studies have been carried out on poly(vinyl chloride) (PVC), and blends of PVC with solution-chlorinated polyethylene (SCPE) and poly(butyl acrylate) (PBA). The PVC used was commercial (suspension-polymerized) or bulk-polymerized. The blends of PVC with PBA were prepared by solvent-casting and those with SCPE by in situ polymerization. PVC samples show shoulders in the scattering spectra, presumably due to crystallites, which persist even in samples which have been solvent cast. Blends of PVC with PBA also show a peak but at a higher ‘d’ spacing. The blends with SCPE which were prepared by in situ polymerization show no such peak. This suggests that the method of preparation prevents the formation of crystallites. An increase in scattering of the PBA blends was observed when the samples were heated to the temperature of phase separation. Neutron scattering studies were also carried out using 2% deuterium labelled PVC in PVC and in the blends. In the PVC this showed chain dimensions in good agreement with predicted values. In the blends, dimensions of the same order were obtained, confirming a molecular dispersion of chains in the single phase, but there was an apparent reduction in the chain dimensions. This could be explained by a true reduction in dimensions or a non-zero A₂ value in the blends.     

PVC的微发泡处理及PVC/CaCO3的原位复合

研究了用原位生成法制备PVC/纳米CaCO3复合母粒的过程. 首先利用混合溶剂将PVC粉料溶胀,同时带入发泡剂偶氮二异丁腈,在112oC下进行固相微发泡. 利用已发泡的PVC,采用原位生成法制备了纳米CaCO3/PVC复合母粒. 通过扫描电镜观察,发现已发泡PVC颗粒表面布满微孔,纳米级CaCO3填充在PVC孔洞里. PVC/纳米CaCO3复合母粒同时起到了增韧增强的作用.     

PVC防水卷材的配方研究

研究了利用废旧软聚氯乙烯回收料(旧料)生产PVC塑料防水卷材的配方及其对卷材拉伸性能的影响。结果表明,PVC塑料卷材的拉伸强度和断裂伸长率随PVC树脂添加比例增加而提高,而相同添加量的SG-3型PVC树脂比SG-5型PVC树脂的拉伸性能高；在试验范围内,增塑剂用量增加,卷材的拉伸强度降低,伸长率先升后降；添加CPE能提高PVC卷材伸长率,但拉伸强度有所下降。当CaCO_3用量低于20份时,卷材的拉伸强度和伸长率随CaCO_3添加量增加而提高。PVC防水卷材的优选配方(质量份)：旧料85份,PVC树脂(SG-3型)15份,DOP 5份,CPE 3份,稳定剂(TLS)0．6份,其它助剂适量。     

增塑剂DOP在软PVC和PVC/ABS共混物中的应用

研究了增塑剂DOP对聚氯乙烯（商品牌号SG-3，SG-5）及PVC／ABS共混物力学和硬度等性质的影响及其机理。结果表明：由于DOP小分子对高分子链的物理隔离作用，当DOP含量高于30％时，随DOP用量的增加，PVC树脂及PVC／ABS的断裂伸长率明显增大，体系的拉伸强度、撕裂强度和硬度等略微下降。     

CaCO3在PVC电缆料中的应用

研究了普通CaCO3填充PVC电缆料的性能，结果表明，理化性能符合要求、杂质含量在极限范围内的普通CaCO3在配方设计合理的情况下可用作PVC电缆料的填料，生产的PVC电缆料J70完全符合国家标准，可以替代活性CaCO3，降低电缆料生产成本。     

Adhesion of Injection Molded PVC to Steel Substrates

Interactions occurring at the interface between injection-molded poly (vinyl chloride) (PVC) and steel substrates that were coated with thin films of aminosilanes were investigated by X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR). The silane films were formed by adsorption of γ-aminopropyltriethoxysilane (γ-APS) or N-(2-aminoethyl-3-aminopropyl)trimethoxysilane (γ-AEAPS) from 2% aqueous solutions onto polished steel substrates. PVC was injection molded onto the silane-primed steel substrates and annealed at temperatures up to 170°C for times as long as 30 min. PVC was peeled off of the primed steel substrates using a 90° peel test and the substrate failure surfaces were thoroughly rinsed with tetrahydrofuran (THF) and distilled water to remove PVC and other compounds that were not strongly bonded to the substrates. The PVC failure surfaces were characterized by attenuated total reflection infrared spectroscopy (ATR) and PVC rinsed off of the substrate failure surfaces was characterized by transmission infrared spectroscopy. The resulting transmission and ATR spectra showed an absorption band near 1650 cm^-1 that was attributed to unsaturation in PVC. The substrate failure surfaces were characterized by XPS; curve-fitting of N(1s) and Cl(2p) high-resolution spectra showed the formation of amine hydrochloride complexes by protonation of amino groups of the silanes with HCl that was liberated from PVC during the onset of thermal dehydrochlorination. Furthermore, quaternization or nucleophilic substitution of labile pendent allylic chloride groups by amino groups on the silanes took place, thus grafting PVC onto the aminosilanes. It was determined that PVC that had β-chloroallyl groupings along its chains showed better adhesion with steel primed with aminosilanes and that generation of allylic chloride groups in PVC chains was the rate-limiting step in the reaction between PVC and aminosilane. Moreover, the effect of crosslinking of silane films on adhesion between PVC and aminosilane primed steel was investigated and it was concluded that interdiffusion of the polymer phase and the silane phase was also critical in obtaining good adhesion.     

纳米晶PVC在PVC／CaCO3复合材料中的作用

研究了不同粒径的纳米晶PVC的增韧、增强作用及对纳米CaCO3改性时偶联剂对材料力学性能的影响。结果表明：两种粒径的纳米晶PVC均能起到显著的增韧和增强作用，且粒径小的纳米晶PVC作用更明显。材料拉伸强度、冲击强度随偶联剂含量的增加而提高。纳米晶PVC和纳米CaCO3使复合材料达到工程材料的标准。     

填料对聚氯乙烯电缆料辐射交联的影响

研究了陶土、Ａｌ（ＯＨ）３、ＣａＣＯ３等三种不同填料对软质聚氯乙烯（ＰＶＣ）电缆料辐射交联的影响,交联剂为三甲氧基丙烷三甲基丙烯酸酯（ＴＭＰＴＭＡ）,由Ｃｏ＾６０γ射线辐照至４．０Ｍｒａｄ。结果表明,填料的加入使ＰＶＣ辐射交联后凝胶含量下降。在相同加入量下,加入ＣａＣＯ３使凝胶含量下降最多,加入Ａｌ（ＯＨ）３次之。与不加填料相比,加入三种填料后均使ＰＶＣ辐射交联后力学性能降低。